Arum Poisoning in Horses

Arum Poisoning in Horses - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost
Arum Poisoning in Horses - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost

What is Arum Poisoning?

The Arum plant produces elegant lilies with long arrow-shaped leaves. It also produces fleshy berries that each contain several seeds. Insoluble calcium oxalate crystals cause the toxicity.  Because of the unpalatable taste and the burning or irritation suffered upon eating, your horse will usually eat very little. Therefore, toxic doses are rare. Poisoning often happens not from your horse eating the plant directly, but rather through indirect means such as Arum plant being accidentally mixed and dried within the hay. Arum is also known as Adam and Eve, and Lord and Ladies.

Due to its bitter taste, your horse will not usually eat the Arum plant unless very hungry. The sap produces pain and extreme irritation upon eating.

Symptoms of Arum Poisoning in Horses

  • If a large amount of the plant has been ingested, the area around the mouth, inside the mouth, and the throat will be affected by the strong irritating toxins 
  • Trembling and unsteady hind legs as they weaken due to the toxin 
  • Abdominal discomfort
  • Depression
  • Colic 
  • Diarrhea
  • Ataxia
  • Dehydration
  • Collapse 


  • The varieties of the Arum plant range in color from purple to a creamy white, including a lime green 
  • The plant has an elegant shape and has a spike that bears the large seed heads 
  • It grows in many areas, often growing to a large size when left alone 
  • The berries or seeds are very toxic and can cause severe poisoning 
  • Self-propagating, it can spread over a wide area within a short time
  • Known as Italian Arum, Black Calla, Starch Root and Cuckoopint
  • Originated from Europe and Near East


Causes of Arum Poisoning in Horses

  • The insoluble calcium oxalate crystals cause the pain when biting into the plant 
  • The crystals have razor sharp edges, and that causes damage to any tissue it touches 
  • The pain is good in a way that it prevents further eating of the plant 
  • Inflammation on the inside of the mouth and throat can be severe 
  • The first step is to wash away around the mouth and irritated areas
  • Flushing water through your horse’s system will help 
  • Severe overdoses can cause harm to the vital organs


Diagnosis of Arum Poisoning in Horses

As far as eating the plant, your horse will usually get a nasty surprise when it bites into the plant, with a very unpalatable taste but more so because of the severe irritation the sap from the plant causes in and around the mouth. Usually they will get away with a mild dose of poisoning. The problem occurs more when the plant is mixed in accidentally with the grass at haymaking time. Even in its dried state, as with a lot of toxic plants, they retain their toxic capacity. And because it is mixed with the hay your horse may eat quite a bit before discovering that unpleasant taste. Careful observation of your horse is always vital to ensure their good health continues. If you notice your horse with any of the symptoms listed above, call your veterinarian as all horses react differently to toxins, and it also depends on their health and how much plant material was ingested. Though blood tests may not provide definitive information, results can indicate changes to organ function. If a tool is needed for more rapid results, a urinalysis may prove to be helpful.

Additionally, the vet will check your horse’s mouth to verify if irritation is present. Plant material still in the mouth may be found. With rapid examination and treatment, the prognosis is good. Always call the veterinarian to assist your horse as poisoning can be fast acting and the sooner you get treatment for your horse, the easier it will be for the animal. Leaving the poison to develop before calling a specialist may result in irreparable damage done to your horse, from which they may never fully recover.



Treatment of Arum Poisoning in Horses

There is no antidote for Arum poisoning in your horse. Symptomatic care is the best on offer. Removing your horse from the paddock to a quiet stall with deep bedding is best, and allow your horse to rest and recover. Analgesics for oral mucosal irritation and pain may be required, and depending on the severity of the poisoning, intravenous fluids and cardiac monitoring may be needed. As your horse recovers, rehydration and electrolyte replacements may be administered as per your specialist’s recommendation. Flushing the toxin out of the system is the best solution. Although the plant can deliver a powerful dose of toxin, it is a rare occurrence because thankfully, the appalling taste does put your horse off from overdosing.

Ensuring your horse has plenty of good quality food at all times, as this will overcome your hungry four legged friend from experimenting by eating unknown plants just to fill his stomach. Always check your hay supplies and when you find a reputable supplier, stick fast to them. So often poisoning comes by way of toxic plants ending up in the hay and dried along with it, only to poison an unsuspecting horse some way down the line. Vigilance is the key to a healthy happy horse.



Worried about the cost of Arum Poisoning treatment?

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Recovery of Arum Poisoning in Horses

Horses are known for their curiosity, and if they are bored or hungry, they will be tempted to try new plants that pop up in their field. That is why observation is vital to prevent toxic weeds taking over in pasturelands, which will ensure your horse has plenty of quality food to eat. Like everyone, your horse can get bored being in the same old paddock, doing the same old routine.

Surprise your horse with variety, different trails to ride, different paddocks if possible, even adding a companion will help keep them entertained. And the companion doesn’t have to be another horse; it could be the family dog who comes along while you are checking over the paddock, the neighbor’s sheep, or even a cow or two. By providing variety, your equine friend will not have to go exploring and get into trouble.



Arum Poisoning Questions and Advice from Veterinary Professionals

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